| | | |
| | x_fline.sa 3.3 1/10/91 | |
| | | |
| | fpsp_fline --- FPSP handler for fline exception | |
| | | |
| | First determine if the exception is one of the unimplemented | |
| | floating point instructions. If so, let fpsp_unimp handle it. | |
| | Next, determine if the instruction is an fmovecr with a non-zero | |
| | <ea> field. If so, handle here and return. Otherwise, it | |
| | must be a real F-line exception. | |
| | | |
| | Copyright (C) Motorola, Inc. 1990 | |
| | All Rights Reserved | |
| | | |
| | For details on the license for this file, please see the | |
| | file, README, in this same directory. | |
| X_FLINE: |idnt 2,1 | Motorola 040 Floating Point Software Package | |
| |section 8 | |
| #include "fpsp.h" | |
| |xref real_fline | |
| |xref fpsp_unimp | |
| |xref uni_2 | |
| |xref mem_read | |
| |xref fpsp_fmt_error | |
| .global fpsp_fline | |
| fpsp_fline: | |
| | | |
| | check for unimplemented vector first. Use EXC_VEC-4 because | |
| | the equate is valid only after a 'link a6' has pushed one more | |
| | long onto the stack. | |
| | | |
| cmpw #UNIMP_VEC,EXC_VEC-4(%a7) | |
| beql fpsp_unimp | |
| | | |
| | fmovecr with non-zero <ea> handling here | |
| | | |
| subl #4,%a7 |4 accounts for 2-word difference | |
| | ;between six word frame (unimp) and | |
| | ;four word frame | |
| link %a6,#-LOCAL_SIZE | |
| fsave -(%a7) | |
| moveml %d0-%d1/%a0-%a1,USER_DA(%a6) | |
| moveal EXC_PC+4(%a6),%a0 |get address of fline instruction | |
| leal L_SCR1(%a6),%a1 |use L_SCR1 as scratch | |
| movel #4,%d0 | |
| addl #4,%a6 |to offset the sub.l #4,a7 above so that | |
| | ;a6 can point correctly to the stack frame | |
| | ;before branching to mem_read | |
| bsrl mem_read | |
| subl #4,%a6 | |
| movel L_SCR1(%a6),%d0 |d0 contains the fline and command word | |
| bfextu %d0{#4:#3},%d1 |extract coprocessor id | |
| cmpib #1,%d1 |check if cpid=1 | |
| bne not_mvcr |exit if not | |
| bfextu %d0{#16:#6},%d1 | |
| cmpib #0x17,%d1 |check if it is an FMOVECR encoding | |
| bne not_mvcr | |
| | ;if an FMOVECR instruction, fix stack | |
| | ;and go to FPSP_UNIMP | |
| fix_stack: | |
| cmpib #VER_40,(%a7) |test for orig unimp frame | |
| bnes ck_rev | |
| subl #UNIMP_40_SIZE-4,%a7 |emulate an orig fsave | |
| moveb #VER_40,(%a7) | |
| moveb #UNIMP_40_SIZE-4,1(%a7) | |
| clrw 2(%a7) | |
| bras fix_con | |
| ck_rev: | |
| cmpib #VER_41,(%a7) |test for rev unimp frame | |
| bnel fpsp_fmt_error |if not $40 or $41, exit with error | |
| subl #UNIMP_41_SIZE-4,%a7 |emulate a rev fsave | |
| moveb #VER_41,(%a7) | |
| moveb #UNIMP_41_SIZE-4,1(%a7) | |
| clrw 2(%a7) | |
| fix_con: | |
| movew EXC_SR+4(%a6),EXC_SR(%a6) |move stacked sr to new position | |
| movel EXC_PC+4(%a6),EXC_PC(%a6) |move stacked pc to new position | |
| fmovel EXC_PC(%a6),%FPIAR |point FPIAR to fline inst | |
| movel #4,%d1 | |
| addl %d1,EXC_PC(%a6) |increment stacked pc value to next inst | |
| movew #0x202c,EXC_VEC(%a6) |reformat vector to unimp | |
| clrl EXC_EA(%a6) |clear the EXC_EA field | |
| movew %d0,CMDREG1B(%a6) |move the lower word into CMDREG1B | |
| clrl E_BYTE(%a6) | |
| bsetb #UFLAG,T_BYTE(%a6) | |
| moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers | |
| bral uni_2 | |
| not_mvcr: | |
| moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers | |
| frestore (%a7)+ | |
| unlk %a6 | |
| addl #4,%a7 | |
| bral real_fline | |
| |end |